The effect of various pathophysiologic states on the oxygenation and metabolism of the gastric surface epithelial cells will be studied using a canine in vivo chambered stomach model. Intracellular oxygen tension and transmembrane potential difference, a measure of cellular metabolism, will be measured with a gold ultramicroelectrodes. Plans for the coming year include studies on the pathophysiology of septic shock and its treatment and studies on the effectiveness of various vasodilators in improving tissue oxygenation and maintaining normal cellular metabolism.